Electronic Monitoring Device

ABSTRACT

An electronic device for monitoring. The electronic device includes a functional module arranged to provide an active function, a communication module arranged to communicate with an external communication device, and an energy harvesting module arranged to transform a source energy from an external source to electrical energy for energising both the communication module and the functional module.

TECHNICAL FIELD

The present invention relates to an electronic monitoring device.Particularly, although not exclusively, the invention relates to anelectronic device and a system including at least one electronic devicefor sensing and monitoring.

BACKGROUND

There are many physical properties that vary with the environment, time,location, etc. Some examples are temperature, light, wind, humidity,sound level, air quality. These properties are important in that theyaffect our health and our comfort. Therefore, it would be beneficial tomonitor and keep track of these physical properties. For example, if thetemperature is too high or too cold, responsible party can remind thepublic to avoid staying out for long or to wear thicker clothes whenthey go out; or if the sound level is too high at a corner of a club,the user can tune down the music volume of one particular microphone.

Many devices are developed to measure these physical properties. Userscan use a conventional mercury thermometer or a digital thermometer tomeasure temperature, or a sound level meter to measure the loudness.Technologies nowadays allow users to read a digital value of themeasurement from the devices directly. In cases where users would liketo measure properties at different location or at a different time, theycan repeat the measurement and record the measurements by pens and paperfor tracking and statistics purpose.

This way of measuring and keeping track of these physical properties aretime-consuming and costly. In one example, the user may have to walkthrough the whole area of a large premise such as a shopping mall or astation to measure the temperature at different location in order toturn up or turn down the temperature of a particular air-conditioner.Additionally, these measuring devices consume a lot of energy, andbatteries may have to be replaced very frequently which cost a lot ofmoney.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there isprovided an electronic device comprising a functional module arranged toprovide an active function, a communication module arranged tocommunicate with an external communication device, and an energyharvesting module arranged to transform a source energy from an externalsource or from the ambient environment to electrical energy forenergising both the communication module and the functional module.

Preferably, the functional module includes at least one sensor forsensing and monitoring.

In one embodiment of the first aspect, the energy harvesting modulecomprises an energy harvester arranged to harvest the source energy fromthe external source.

In one embodiment of the first aspect, the source energy includes lightenergy.

In one embodiment of the first aspect, the energy harvester includes aphotovoltaic panel.

In one embodiment of the first aspect, the source energy includesradio-frequency waves.

In one embodiment of the first aspect, the radio-frequency waves arearranged to be radiated from an antenna, which is connected to aradio-frequency identification (RFID) reader.

In one embodiment of the first aspect, the energy harvester comprises aradio-frequency energy harvesting antenna.

In one embodiment of the first aspect, the energy harvesting modulefurther comprises an energy storage arranged to store the transformedelectrical energy.

In one embodiment of the first aspect, the energy harvesting modulefurther comprises a voltage regulator arranged to stabilise and regulatea voltage output of the electrical energy providing to the functionalmodule and the communication module.

In one embodiment of the first aspect, the communication modulecomprises a communication antenna arranged to communicate with theexternal communication device.

In one embodiment of the first aspect, the communication module furthercomprises a memory chip arranged to store an output from the functionalmodule.

In one embodiment of the first aspect, the communication module includesa Bluetooth communication module.

In one embodiment of the first aspect, the communication module includesa Bluetooth Low Energy (BLE) communication module.

In one embodiment of the first aspect, the communication module includesa radio-frequency communication module.

In one embodiment of the first aspect, the external communication deviceincludes a radio-frequency identification (RFID) reader with an antenna.

In one embodiment of the first aspect, the communication module includesa radio-frequency identification (RFID) transponder.

In one embodiment of the first aspect, the external communication deviceincludes an RFID reader with antenna arranged to energise both the RFIDtransponder and the functional module when upon the RFID reader readsthe RFID transponder.

In one embodiment of the first aspect, the functional module includes asensor.

In one embodiment of the first aspect, wherein the sensor is arranged todetect one or more attributes of an environment or an object bymonitoring one or more electronic outputs, and wherein the one or moreelectronic outputs change in response to the one or more attributes ofthe environment or the object.

In one embodiment of the first aspect, the sensor includes a temperaturesensor and/or a humidity sensor.

In one embodiment of the first aspect, the functional module includes aclock arranged to determine a time stamp associated with the one of moreelectronic outputs.

In accordance with a second aspect of the invention, there is provided amonitoring system comprising at least one electronic device, wherein theexternal communication device is arranged to communicate with the atleast one electronic device so as to monitor one or more attributes ofan environment or an object.

In one embodiment of the second aspect, the external communicationdevice is arranged to repeatedly communicate with the at least oneelectronic device in a predetermined time interval so as to monitor theone or more attributes of the environment or the object within apredetermined time period.

In one embodiment of the second aspect, the external communicationdevice is further arranged to determine a position of each of theelectronic device based on a signal received by the communicationdevice.

In one embodiment of the second aspect, the one or more attributesinclude temperature and/or humidity.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way ofexample, with reference to the accompanying drawings in which:

FIG. 1 is a functional block diagram of an electronic device inaccordance with one embodiment of the present invention;

FIG. 2 is a functional block diagram of the electronic device using RFIDin accordance with one embodiment of the invention;

FIG. 3 is a circuit diagram of the energy harvesting module of theelectronic device of FIG. 2;

FIG. 4A is an exploded view of an embodiment of the electronic device ofFIG. 2;

FIG. 4B is a photographic image of a printed circuit board of theelectronic device of FIG. 4A;

FIG. 4C is a graph showing the return loss and isolation of the energyharvesting antenna and the communication antenna of the electronicdevice of FIG. 4A;

FIG. 4D is a graph showing the power transfer coefficient of the energyharvesting antenna and the communication antenna of the electronicdevice of FIG. 4A;

FIG. 5 is a functional block diagram of an electronic device using BLEin accordance with one embodiment of the invention;

FIG. 6 is a circuit diagram of the energy harvesting module of theelectronic device of FIG. 5;

FIG. 7A is a photographic image showing a top view of the electronicdevice of FIG. 5;

FIG. 7B is a photographic image showing a top view of the electronicdevice of FIG. 7A, wherein the top cover is removed to reveal an energyharvester on the printed circuit board of the electronic device;

FIG. 7C is a photographic image of an opposite side of the printedcircuit board of the electronic device of FIG. 7B;

FIG. 8 is a functional block diagram of the electronic device using RFIDand BLE in accordance with one embodiment of the invention;

FIG. 9A is a photographic image showing a top view of the electronicdevice of FIG. 8, with an energy harvester on a printed circuit board ofthe electronic device;

FIG. 9B is a photographic image of an opposite side of the printedcircuit board of the electronic device of FIG. 9A;

FIG. 9C is a graph showing the return loss of the BLE antenna of theelectronic device of FIG. 9A;

FIG. 9D is a graph showing the return loss of the RFID antenna of theelectronic device of FIG. 9A;

FIG. 10 is a schematic diagram illustrating a monitoring system withmultiple electronic devices in accordance with one embodiment of theinvention; and

FIG. 11 is a schematic drawing illustrating a monitoring system withmultiple electronic devices in accordance with one embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is shown an example embodiment of anelectronic device 100 comprising a functional module 130 arranged toprovide an active function, a communication module 120 arranged tocommunicate with an external communication device 140 and an energyharvesting module 110 arranged to transform a source energy from anexternal source or from ambient environment to electrical energy forenergising both the communication module 120 and the functional module130.

In this embodiment, the electronic device 100 may be a detector or asensor for use in a monitoring system. The functional module 130 mayinclude one or more electronic components which require electricalenergy so as to provide an active function. In a preferred embodiment,by monitoring one or more electronic outputs, the sensor may detect oneor more attributes of an environment or an object, such as but notlimited to humidity and temperature. The one or more electronic outputsmay change in response to the change of the one or more attributes beingmonitored. For example, the sensor may be a temperature sensor or ahumidity sensor for detecting temperature and humidity. Alternatively,other sensors or detectors may also be used, for example but not limitedto a light sensor, a motion sensor, a pressure sensor, an air qualitymonitoring detector, flow meter and altitude sensor, etc. In someembodiments, there may be more than one sensor in the functional module130.

The sensor may be in direct contact with or be positioned at a distancefrom the environment or the object to be monitored. For example, thesensor may be exposed to air in a room, or attached to a surface of anobject, wherein upon contact, electrical parameters such as voltageoutputs, capacitance and resistance may change in response to the changein one or more attributes. By monitoring the electronic outputs or theelectrical parameters, the one or more attributes of the environment orthe object can be detected. In an alternative example, the sensor may bepositioned at a distance from an object for measuring the one of moreattributes such as temperature or the relative movement of the object.

Additionally or alternatively, the functional module 130 may compriseother functional units or electronic components such as an alarm, one ormore indicators, a processor and a memory, so as to provide other typesof active function.

The communication module 120 may be an RFID or a BLE communicationmodule or any other communication standard such LoRa, WiFi, etc., whichrequires electrical energy to transmit and receive signals to and froman external communication device 140. Preferably, the communication iswireless, but may also be wired. The electronic outputs may betransmitted from the functional module 130 to the communication module120, which may then be transmitted to an external communication device140 for processing and further action and analysis.

The electronic device 100 further comprises an energy harvesting module110 arranged to harvest energy from an external source so as to supplysufficient energy for powering the communication module 120 and thefunctional module 130 during an operation of the electronic device 100.Preferably, the energy harvesting module 110 may comprise an energyharvester arranged to harvest the source energy from the externalsource. The source energy may take various forms, such as light energyand electromagnetic energy, and accordingly, the external sourcecomprising the source energy may be the natural physical environment ora device. The source energy may be further transformed to electricalenergy required by the communication module 120 and/or the functionalmodule 130.

The external source and the external communication device may be of thesame device in one embodiment. For example, a radio-frequencyidentification (RFID) reader may be used for energising andcommunicating with the electronic device 100. In another embodiment, theexternal source may be a different source or device from the externalcommunication device. For example, the external source can be sunlight,a light apparatus, an inductive coil, or an external power transmitter,etc. Alternatively, the energy may be light or other sources of energyobtainable from the ambient environment The external communicationdevice may be a computer, a mobile phone, a tablet, etc.

Referring now to FIG. 2, there is shown an electronic device 200 usingRFID in accordance with one embodiment of the invention. In thisexample, the communication module 220 is a radio-frequency (RF)communication module such as a radio-frequency identification (RFID)transponder arranged to communicate with an RFID reader 240. RFID reader240 can be a fixed RFID reader or a handheld reader, which are connectedto an antenna. Preferably, the RFID reader 240 arranged to radiateradio-frequency (RF) waves for energising and communication with theRFID transponder 220.

In this embodiment, the energy harvesting module 210 comprises an energyharvester 212 which may include, a radio-frequency (RF) energyharvesting antenna for transforming the received radio-frequency (RF)waves to electrical energy. Optionally, the energy harvester may alsoinclude an energy storage 214 and a voltage regulator 216 in connectionwith the RF energy harvesting antenna 212 for temporally storing theharvested energy and regulating the electrical energy outputs from theenergy harvesting antenna 212 and/or the energy storage 214.

With reference to FIG. 3, there is provided an energy harvesting module210 of the electronic device 200. In this example, the energy harvester212 includes a voltage multiplier structure for convertingradio-frequency (RF) waves to DC power by rectifying the peak-to-peakvoltage of the RF waves. Electronic components such as diodes andcapacitors may be used to provide voltage offset, rectification,amplification, etc. The transformed electrical energy may be then storedin the energy storage 214 which comprises a pair of capacitively-coupledconductors for charging and discharging. Additionally or optionally, theenergy storage 214 may also include a rechargeable battery for storingthe harvested energy for prolonged usage when the electronic device 200is no longer being exposed to an external energy source. The voltageregulator 216 may regulate the electrical output from the energy storage214 and/or the RF energy harvesting antenna 212 at a desired voltagesince electrical energy harvested from different energy source mayproduce a different voltage output. This may damage the electronicdevice 200 in the case where the voltage output exceeds the thresholdvalue of one or more electronic components.

Referring back to FIG. 2, the functional module 230 includes a sensor232. The senor 232 may be a temperature or a humidity sensor wherebyelectronic outputs such as current and capacitance change in response toa change in temperature or humidity of the environment or an object. Thefunctional module 230 may further comprises a clock or timer fordetermining a time stamp associated with the electronic outputs. Theelectronic outputs may be transmitted to the RFID transponder or tagwhich comprises a memory chip 222 and a communication antenna 224. Theelectronic outputs transmitted from the functional module 230 may bestored in the memory chip 222. Preferably, the memory chip 222 is amemory which can be read by an external communication device 240 whendesired for retrieving the detected electronic outputs. In the RFIDtransponder, a communication antenna 224 is operably connected to theRFID chip 222 for communicating the detected electronic outputs to anexternal communication device 240.

Preferably, the antenna 224 may be a radio-frequency identification(RFID) antenna for transmitting and receiving radio-frequency (RF) wavesto and from the radio-frequency identification (RFID) reader 240. TheRFID transponder may be passive, wherein the electronic device 200 onlycommunicates with the RFID reader when received a signal from thereader. In this example, a user may radiate radio-frequency (RF) wavestowards the electronic device 200 using an RFID reader for retrievingthe detected electronic outputs and for further determination andanalysis of the one of more attributes of the environment or the object.At the same time, the radio-frequency waves radiated from the RFIDreader 240 may also be provided as an external source of energy forenergising the electronic device 200. Alternatively, the RFID reader 240may be used only for communication with the RFID tags, and theelectronic device 200 may be powered by other RF energy sources.

With reference to FIGS. 4A and 4B, there is shown an embodiment of theelectronic device 400. In this embodiment, the electronic device 400comprises a housing 460, wherein the housing 460 is substantiallyrectangular, but it may be shaped differently in other embodiments. Forexample, in other embodiments, the electronic device 400 may be squareor trapezoidal. The housing 460 is preferably made of light-weighted buttough material such as plastic or carbon fibre, such that the electronicdevice 400 is substantially shockproof and can be easily mounted orattached to an object. One or more sealing material may be positionedaround the opening of the housing 460 for providing water-tight sealingto protect the electronics components of the electronic device 400against water and dust.

A printed-circuit board 450 of the electronic device 400 is positionedinside the housing 460. With reference to FIG. 4B, the energy harvestingmodule 410, the communication module 420 and the functional module 430may be soldered onto the printed circuit board 450. Each of the energyharvesting antenna 412 and the communication antenna 424 may bepositioned or defined on the same or different edges of the printedcircuit board 450. In one example embodiment, the printed circuit board450 is 82 mm in length, 51 mm in width and 2.3 mm in height, wherein thehousing 460 is 86.2 mm in length, 55.1 mm in width and 6.8 mm in height.The communication range of the electronic device 400 with an RFID readermay be up to 3 m. In other embodiments, the dimensions of the device 400and the communication range may increase or decrease in differentapplications.

With reference to FIGS. 4C and 4D, there is shown experimental resultsof the electronic device 400 in accordance with an embodiment of thepresent invention. In the experiment, the RF energy harvesting antennaand the RFID communication antenna were specified as ports 1 and 2respectively, and the performances of the electronic device wereevaluated by simulations.

Referring to the plots representing the return loss and the powertransfer coefficients, the two antennas operated under the samefrequency band around the frequency range of 860 MHz to 960 MHz. Inaddition, it was also observed that a mutual coupling between the twoantennas is below −5 dB within such frequency band.

Referring now to FIG. 5, there is shown an electronic device 500 usingBLE in accordance with another embodiment of the invention. In thisembodiment, the harvester 512 is a photovoltaic panel for transforminglight energy provided by a light source, such as from sunlight or alight apparatus, to electrical energy. Alternatively, the harvester 512may be a coating of photovoltaic paint on the outside of the electronicdevice 500 for receiving light energy from external environment.Advantageously, photovoltaic panels may be used for harvesting a higheramount of energy in an environment which may provide a substantiallystable or sufficient source of ambient lighting, so as to powercommunication and/or functional modules which may require a higheroperation rating.

With reference to FIG. 6, the energy harvester 512 of the electronicdevice 500 includes at least one photovoltaic panel for transforminglight energy to electrical energy. One or more ultra-capacitors orrechargeable battery cells may be used as energy storage 514 to improvethe performance during a low light intensity situation. The transformedelectrical energy may then be stored in the energy storage 514 beforepassing through a voltage regulator 516 to supply energy at a desiredvoltage to the rest of the electronic device 500.

Referring back to FIG. 5, the functional module 530 includes one or moresensor 532. Similar to the previous embodiments, the sensor 532 may alsodetect temperature and/or humidity of the environment or the attachedobject by transmitting the electronic outputs and associated time stampto the communication module 520. In this embodiment, the communicationmodule 520 includes a Bluetooth communication module. For example, itmay comprise a Bluetooth Low Energy (BLE) communication module. TheBluetooth communication module includes a memory 522 which stores theelectronic outputs from the functional module 530 and a communicationantenna 524 operably connected to the memory 522 for communicating thedetected electronic outputs to an external communication device 540. Inthis embodiment, the antenna 526 is a Bluetooth Low Energy (BLE) antennafor actively and continuously broadcasting the detected electronicoutputs to the external communication device 540 at a regularpredetermined time interval. The external communication device 540 maybe a smart device, computer, a laptop or a mobile phone capable ofreceiving the broadcasted signals from the electronic device 500.

With reference to FIGS. 7A to 7C, there is shown an embodiment of theelectronic device 700. The electronic device 700 includes a non-metalhousing 760, wherein the housing 760 is substantially square. Thehousing 760 is preferably made of light-weighted but tough material suchas plastic or carbon fibre, such that the electronic device 700 issubstantially shockproof and can be easily mounted or attached to anobject. Preferably, there is a cut-through or a transparent portion onthe top of the housing 760 such that a photovoltaic panel 712 can beexposed and receives light energy from the outside environment. As shownin FIG. 7B, the photovoltaic panel 712 can be mounted on a printedcircuit board and being placed directly under the housing 760.

A printed-circuit board 750 of the electronic device 700 is positionedinside the housing 760. Referring to FIG. 7C, at least part of theenergy harvesting module 710, the communication module 720 and thefunctional module 730 may be soldered onto the printed circuit board750. In one example embodiment, the printed circuit board 750 is 38 mmin length, 38 mm in width and 3.7 mm in height, wherein the housing 760is 42 mm in length, 42 mm in width and 6.6 mm in height. In otherembodiments, the dimensions of the device 700 may increase or decreasein different applications.

With reference to FIG. 8, there is shown an alternative embodiment of anelectronic device 800 using both RFID and BLE. In this embodiment, theenergy harvesting module 810 comprises a photovoltaic panel 812 forharvesting light energy from a light source such as sunlight or a lightapparatus to electrical energy for energising the electronic componentsof the electronic device 800.

In this embodiment, a sensor 832 is included to detect temperature andhumidity of the environment or an attached object. The detectedelectronic outputs and the associated time stamp are transmitted to aduel RFID and BLE communication module 820. The communication module 820comprises a RFID chip 822, a radio-frequency identification (RFID)antenna 824 and a Bluetooth-low-energy (BLE) antenna 826 and a BLEmemory 828. The electronic outputs transmitted from the functionalmodule 830 are stored in the RFID chip 822.

The RFID antenna 824 is connected to the RFID chip 822 for communicatingthe detected electronic outputs to an external communication device 840.In this embodiment, the BLE antenna 826 actively broadcasts the detectedelectronic outputs to an external communication device 840 while thedetected electronic outputs are being written into the RFID chip 822 ata regular predetermined time interval. The external communication device840 may be a smart device, laptop, a mobile phone, or a computer systemcapable of receiving the broadcasted signals from the electronic device800.

A user may also utilize the RF communication module to retrieve thedetected electronic outputs at a regular predetermined time interval andreview a sensing log from a computer system or a mobile phone formonitoring and analysing the one or more attributes of the environmentor the object. Preferably, the RFID antenna 824 can transmit and receiveradio-frequency (RF) waves to and from a radio-frequency identification(RFID) reader 840. Therefore, a user can also radiate radio-frequency(RF) waves using an RFID reader towards the electronic device 800 forretrieving the detected electronic outputs and for determination andanalysis of the one of more attributes of the environment or the object.

Optionally, the energy harvesting module may comprise both aphotovoltaic panel as well as an RF energy harvesting antenna so as tomaximize the energy harvesting capability of the electronic device. Inthis example, the recorded electronic outputs stored in the memory chipmay be read even when there is no sufficient light energy in the ambientor the BLE communication module does not have sufficient power tooperate, a user may use a RFID reader to energise the RFID tag so as toread the output stored in the memory chip.

With reference to FIGS. 9A and 9B, there is show an embodiment of anelectronic device 900. The electronic device 900 includes a non-metalhousing (not shown) which may be similar to the previous embodiments asdiscussed. Similarly, there is a cut-through or a transparent portion onthe top of the housing such that a photovoltaic panel 912 can be exposedand receive light energy from the external environment. As shown in FIG.9A, the photovoltaic panel 912 can be mounted on a printed circuit boardand being placed directly under the housing.

A printed-circuit board 950 of the electronic device 900 is positionedinside the housing. At least part of the energy harvesting module, thecommunication module and the functional module may be soldered onto theprinted circuit board 950. The RFID antenna 924 and the BLE antenna 926are each positioned on one edge of the printed circuit board 950. In anexample embodiment, the printed circuit board 950 is 64 mm in length, 46mm in width and 4 mm in height. In other embodiments, the dimensions ofthe printed circuit board 950 may increase or decrease in differentapplications.

With reference to FIGS. 9C and 9D, there is shown simulation results ofthe electronic device 900. In the simulation, the performances of theBLE communication antenna and the RFID communication antenna wereevaluated. Referring to the plots representing the return loss, the BLEand the RFID antennas operated at two different frequency ranges at 2.4GHz to 2.5 GHz and 920 MHz to 925 MHz respectively.

Referring now to FIG. 10, there is shown a schematic diagramillustrating a monitoring system 10 with multiple electronic devices 800in accordance with one embodiment of the invention. The monitoringsystem 10 comprises multiple electronic devices 800 arranged for sensingand an external communication device 30 is arranged to communicate withmultiple electronic devices 800 so as to monitor one or more attributesof an environment or an object. The external communication device 30 isarranged to repeatedly communicate with the multiple electronic devices800 through one or more communication links in a predetermined timeinterval so as to monitor the one or more attributes of the environmentor the object within a time period. The one or more attributes includebut not limited to temperature and humidity.

In an example embodiment, the monitoring system 10 can be applied to anInternet-of-Thing (IOT) application of an automatic airflow andtemperature control of a centralised air-conditioning system. In thisembodiment, there are five electronic devices 800 each positioned at adifferent location of a building. In some other embodiments, more orless electronic devices may be used for monitoring there may be twentyelectronic devices 800 in one example, or there may be three electronicdevices 800 in another example. User can place each electronic device800 at a desired location targeted for monitoring e.g. different roomsin an apartment, different floors of a building, different locations ina large air-conditioned premises such as airport, museum, shopping malletc. Preferably, the electronic devices 800 are exposed to light such asnatural light from the sun or light from a light apparatus so that theenergy harvester of the electronic device 800 can transform light energyto electricity for energising the device.

Upon being energised, the sensors of the electronic devices 800 detectthe temperature and humidity of their proximate surrounding. Thedetected temperature and humidity, together with the corresponding timestamp and the unique ID of each device are transmitted to a memory chipor a temporary storage of the electronic devices 800. The transmitteddata are being broadcasted to a smart device 30 via a Bluetoothcommunication link 12 and then further to server 20 via a communicationlink 14. The communication link 14 may be a Bluetooth communication linkor other wireless or wired communication link such as WiFi, Zigbee, 3Gand fixed network. In another embodiment, the detected temperature andhumidity may be directly transmitted to the external communicationdevice 30 via a Bluetooth communication link. The detected temperatureand humidity are broadcasted at a regular predetermined time interval,e.g. every few seconds, minutes or every hour. Preferably, the positionof each of the electronic device 800 can be obtained from thebroadcasting signal such that the user can easily track the detectedattributes with their corresponding location.

The external communication device 30 can be a laptop 30A or a smartdevice 30B, but other wireless communication devices which are capableof receiving the detected signals from the electronic devices 800 mayalso be used. The laptop 30A may have a programme which allows the userto monitor and analyse the detected signals, whereas the user may alsouse a smart device 30B with a pre-downloaded app for viewing andmonitoring. According to the detected temperature and humidity of theelectronic devices 800 placed at different location, the user may takecorresponding action to ensure a pleasant environment e.g. turning upthe temperature of the air-conditioning if the detected temperature istoo low for people to feel comfortable or turning down the temperatureof the air-conditioning if the outside temperature is too high.Optionally, the user may link the detected temperature and humidity to acentralised system for automatic tuning.

In this embodiment, the user may also retrieve the detected temperatureand humidity by radiating radio-frequency (RF) waves using a RFID readertowards the electronic devices 800. The RFID reader can retrieve thedetected temperature and humidity, as well as the corresponding timestamp from the electronic devices 800 through a backscattered signalfrom the electronic devices 800. This monitoring system 10 isadvantageous in that it allows a smart centralised air-conditioningsystem which enhanced passengers and customers' experience by providinga pleasant environment. It is further advantageous in that thismonitoring system 10 requires low maintenance and investment cost sincethe electronic devices 800 make use of renewable energy and batteryreplacement is not required.

FIG. 11 is a schematic drawing illustrating a monitoring system 40 withmultiple electronic devices 200 in accordance with one embodiment of theinvention for monitoring and tracking individual package's temperatureand humidity in cold-chain logistic. In this embodiment, each electronicdevice 200 is placed inside an individual package loaded in acompartment of a truck, light source may not be available. A high powerRFID reader 50A with an RFID antenna is positioned at one end of thetruck to energise the electronic devices 200 by radiatingradio-frequency (RF) waves towards the devices. The high power RFIDreader and antenna enables long and indirect communication range suchthat the RFID may be placed at any location in the compartment of thetruck where the electronic devices 200 can receive the radio-frequency(RF) waves. Upon being energised, the sensor of the electronic devices200 detect temperature and humidity of individual packages which arethen being stored in a RFID chip of the electronic devices 200. The RFIDreader can communicate with the electronic devices 200 for retrievingthe detected temperature and humidity regularly. The user can thereforemonitor the temperature and humidity history of individual package fromthe RFID reader.

In another example embodiment, the user may use a handheld RFID reader50B for identifying and monitoring an individual package without openingup the package. By bringing the handheld RFID reader 50B close to theindividual package, the user can retrieve the unique ID number of theelectronic device 200 and the temperature and humidity detection historyof the package during the whole transportation period. This isadvantageous in that temperature and humidity can be monitored even in adark confined area, especially in the setting of transporting food whichmust be kept at a certain temperature for health concern, ortransporting a large amount of individual packages where user can easilyidentify the packages.

These embodiments of the present invention may be advantageous in thatthe electronic device comprises an energy harvesting module forenergising the electronic device, which requires low maintenance andinvestment cost since battery replacement is not necessary. In addition,the electronic device does not require a continuous supply of wiredelectrical energy source, therefore the simplifying the installationprocess of the electronic devices for use in a monitoring system.

It is further advantageous in that the detected signals detected by theelectronic device can be sent wirelessly through Bluetooth and RFIDcommunication link which allows easy monitoring of one or moreattributes of the environment or the object. This enables a smart systemfor applying in many different areas such as centralisedair-conditioning system for enhancing passengers and customers'experience by providing a pleasant environment, as well as cold-chainlogistic for easy tracking and monitoring individual packages.

It will also be appreciated that where the methods and systems of thepresent invention are either wholly implemented by computing system orpartly implemented by computing systems then any appropriate computingsystem architecture may be utilized. This will include stand-alonecomputers, network computers and dedicated hardware devices. Where theterms “computing system” and “computing device” are used, these termsare intended to cover any appropriate arrangement of computer hardwarecapable of implementing the function described.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the invention as shown inthe specific embodiments without departing from the spirit or scope ofthe invention as broadly described. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive.

Any reference to prior art contained herein is not to be taken as anadmission that the information is common general knowledge, unlessotherwise indicated.

1. An electronic device comprising: a functional module arranged toprovide an active function; a communication module arranged tocommunicate with an external communication device; and an energyharvesting module arranged to transform a source energy from an externalsource or from ambient environment to electrical energy for energisingboth the communication module and the functional module.
 2. Theelectronic device in accordance with claim 1, wherein the energyharvesting module comprises an energy harvester arranged to harvest thesource energy from the external source.
 3. The electronic device inaccordance with claim 2, wherein the source energy includes lightenergy.
 4. The electronic device in accordance with claim 3, wherein theenergy harvester includes a photovoltaic panel.
 5. The electronic devicein accordance with claim 2, wherein the source energy includesradio-frequency waves.
 6. The electronic device in accordance with claim5, wherein the radio-frequency waves are arranged to be radiated from aradio-frequency identification (RFID) reader.
 7. The electronic devicein accordance with claim 5, wherein the energy harvester comprises aradio-frequency energy harvesting antenna.
 8. The electronic device inaccordance with claim 1, wherein the energy harvesting module furthercomprises an energy storage arranged to store the transformed electricalenergy.
 9. The electronic device in accordance with claim 1, wherein theenergy harvesting module further comprises a voltage regulator arrangedto stabilise and regulate a voltage output of the electrical energyproviding to the functional module and the communication module.
 10. Theelectronic device in accordance with claim 1, wherein the communicationmodule comprises a communication antenna arranged to communicate withthe external communication device.
 11. The electronic device inaccordance with claim 10, wherein the communication module furthercomprises a memory chip arranged to store an output from the functionalmodule.
 12. The electronic device in accordance with claim 10, whereinthe communication module includes a Bluetooth communication module. 13.The electronic device in accordance with claim 12, wherein thecommunication module includes a Bluetooth Low Energy (BLE) communicationmodule.
 14. The electronic device in accordance with claim 10, whereinthe communication module includes a radio-frequency communicationmodule.
 15. The electronic device in accordance with claim 14, whereinthe external communication device includes a radio-frequencyidentification (RFID) reader.
 16. The electronic device in accordancewith claim 14, wherein the communication module includes aradio-frequency identification (RFID) transponder.
 17. The electronicdevice in accordance with claim 16, wherein the external communicationdevice includes an RFID reader arranged to energise both the RFIDtransponder and the functional module when upon the RFID reader readsthe RFID transponder.
 18. The electronic device in accordance with claim1, wherein the functional module includes a sensor.
 19. The electronicdevice in accordance with claim 18, wherein the sensor is arranged todetect one or more attributes of an environment or an object bymonitoring one or more electronic outputs, and wherein the one or moreelectronic outputs change in response to the one or more attributes ofthe environment or the object.
 20. The electronic device in accordancewith claim 18, wherein the sensor includes a temperature sensor and/or ahumidity sensor.
 21. The electronic device in accordance with claim 1,wherein the functional module includes a clock arranged to determine atime stamp associated with the one of more electronic outputs.
 22. Amonitoring system comprising at least one electronic device inaccordance with claim 1; wherein the external communication device isarranged to communicate with the at least one electronic device so as tomonitor one or more attributes of an environment or an object.
 23. Themonitoring system in accordance with claim 22, wherein the externalcommunication device is arranged to repeatedly communicate with the atleast one electronic device in a predetermined time interval so as tomonitor the one or more attributes of the environment or the objectwithin a predetermined time period.
 24. The monitoring system inaccordance with claim 22, wherein the external communication device isfurther arranged to determine a position of each of the electronicdevice based on a signal received by the communication device.
 25. Themonitoring system in accordance with claim 22, wherein the one or moreattributes include temperature and/or humidity.